Thorin was born in T.A.2746, presumably in the Lonely Mountain where his grandfather, Thrór, was King under the Mountain. Thorin was still a youngster (aged c. 24), by Dwarves' reckoning, when the dragon Smaug descended upon the mountain of Erebor in flames. Smaug left the mannish town of Dale in ruins and killed many dwarves who were inside the mountain. Thrór and Thráin (Thorin's father) escaped using a secret Back Door. Meanwhile Thorin was one of the few Dwarves who were not inside the mountain at the time. Thus the surviving Dwarves of Erebor were driven into exile and Thrór, Thráin, and Thorin fled south.[1][4]

Weary, elderly and disillusioned, Thrór departed from Dunland with Nár. They came to Azanulbizar and the Eastern gate of Moria, which they found was open. Whilst Nár stayed behind (and urged his companion to do the same) Thrór approached and entered the gate, and was murdered by Azog. He added insult to injury by branding Thrór's brow with the name 'AZOG' in Dwarfrunes. Thus it was that the War of the Dwarves and Orcs began following the return of Nár, who bore the news to Thráin.[1]

Mikel Janin - Battle of Azanulbizar

The war was fought long and hard between the two races, ultimately ending in a pyrrhic Dwarven victory at the Battle of Azanulbizar in T.A.2799. Both Thráin and Thorin were wounded during this battle and Frerin (Thorin's brother) was killed. When his shield broke, in its stead he used an oak branch to block the blows of his foes.[8] Despite victory no Dwarf dared to re-enter Moria out of fear of Durin's Bane.[9]

In memory of this, Thorin swore to always bear a plain shield of oak with no device until he should be hailed king,[10] and thus he earned the epithet Oakenshield.

Thráin, Thorin, and the other survivors of Durin's Folk left Azanulbizar and returned to Dunland. However they soon began to wander Eriador before settling at last in the Blue Mountains. Here they prospered in their own fashion, forging iron objects and increasing their numbers (albeit, due to a scarceness of Dwarf-women, very slowly, and by wandering Longbeards who heard of his dwelling). Nonetheless they all still longed to return to the Lonely Mountain.[1]

By this time Thráin was in possession of the last of the Seven Rings of power. It is possible that as Sauron's power grew so too did the ring's influence over Thráin. His burning desire for gold and to return to the Lonely Mountain became too great and in T.A.2841 he set out to return. Thorin was never to see his father again for Sauron captured and imprisoned Thráin in Dol Guldur. Thus it was that in T.A.2850, following Thráin's death, Thorin became the King of Durin's Folk at the age of ninety-five. Thorin and his people were content living in the Blue Mountains and Eriador but as the years waned Thorin's desire to return to Erebor grew.[11]

The fortunes of the House of Durin changed when Thorin met Gandalf by chance in T.A.2941.[note 1] They then proceeded to go to Thorin's Halls. There they discussed their tales and Gandalf formulated a plan. Gandalf knew that Sauron could have potentially used Smaug with devastating effect. Therefore both he and Thorin had a shared interest in removing Smaug. Gandalf wanted Thorin and a company of dwarves to travel to the Lonely Mountain taking Bilbo Baggins with them. Gandalf's instinct was that the Quest for Erebor would only be successful if Bilbo accompanied them.

Thorin Oakenshield at Bag End

Therefore Gandalf invited Thorin and other Dwarves to Hobbiton of the Shire, instructing them to look for a smial whose door was marked with the sign of the thief (as the dwarves had gotten it into their head that Bilbo was a thief). Thus Thorin found himself in Bag End, where they perused the hobbit's hospitality. However, Thorin and the dwarves were not convinced; it was not until Gandalf revealed Thrór's Map and key that Thorin was convinced that the quest would be profitable to him. Even after the "Unexpected Party" Gandalf only persuaded Thorin to take Bilbo on the morning that they set off.[13]

Thus it was that in T.A.2941 Thorin set off for the Lonely Mountain with Gandalf, Bilbo Baggins, Fíli and Kíli, Balin, Dwalin, Dori, Nori, Ori, Óin, Glóin, Bifur, Bofur, and Bombur. A short time into the journey the adventurers found a Troll's cave. Here they found a hoard of treasure which included blades made in the ancient city of Gondolin. Bilbo found a knife that he named Sting, Gandalf acquired Glamdring and meanwhile Thorin found Orcrist.[14] Whilst Thorin and Company were in RivendellElrond read the inscriptions on the blades and informed them of their sword's histories. He also read the moon-letters on Thrór's map; it read "stand by the grey stone when the thrush knocks [...] and the setting sun with the last light of Durin's Day will shine upon the keyhole."[15]

Upon reaching Esgaroth, the closest settlement to the Lonely Mountain, Thorin was greeted warmly and the men of Lake-town hailed the return of the King under the Mountain.[2] They soon reached the Lonely Mountain itself and "with the last light of Durin's Day" they found the secret side-door, using the key to open it.[16] Thorin sent Bilbo in to carry out his duty as their 'esteemed burglar'. This enraged Smaug who sought to destroy the burglar and take out his vengeance on the Lake-men.[17] The dragon was slain by Bard who pierced an un-armoured spot on the dragon's underside.[18]

Upon hearing the news of the death of Smaug, Thorin was overcome by greed. He fortified the main entrance to the mountain and refused to share any of the treasure. Hosts of Wood-elves and Lake-men approached the mountain led by the Elvenking and Bard respectively. Thorin refused to accept their claims to a share in the treasure and sent for his cousin, Dáin Ironfoot, who brought more than five-hundred Dwarves from the Iron Hills.[19] Bilbo sought to bring an end to the dispute; to this end he secretly gave the Arkenstone to Bard and the Elvenking to use in making a deal with Thorin. When Thorin heard about Bilbo's actions he was furious and felt betrayed by the Hobbit.[20]

However all disputes were cast aside when the army of Bolg, Azog's son, suddenly attacked. Thus the three armies of Elves, Men, and Dwarves united against the two armies of Goblins and Wargs: the Battle of Five Armies had begun. As the battle drew on, Thorin leapt from the front gate and rallied all Elves, Men, and Dwarves to him. The armies of the free peoples of Middle-earth emerged triumphant. Nonetheless Kíli and Fíli were killed and Thorin was gravely wounded. Before he died Thorin spoke to Bilbo and commended his good character, courage and friendship. With that, he died. He was laid to rest deep within the Lonely Mountain. Bard of Dale placed the Arkenstone upon Thorin's chest, whilst the Elvenking laid Orcrist upon Thorin's tomb.[21]

Thorin did not live to enjoy his triumph or his treasure. Pride and greed overcame him in spite of my warning—Gandalf[12]

Thorin was capable of being stubborn, proud, and greedy. According to Gandalf he was, from the beginning, contemptuous about the notion that Bilbo should go with him on his long-desired adventure to the Lonely Mountain; he thought that Gandalf was trying to mock him and make him look foolish. Indeed, Thorin found it difficult to accept the advice of Gandalf at all, believing that he should have been drawing plans for war and battle rather than planning to use a Hobbit as a burglar. But he gradually came to respect the Hobbit's value to his quest, as Bilbo again and again proved his stealth and courage. Thorin's most coveted prize was the Arkenstone, something which Bilbo believed was not only the heart of the mountain but the heart of Thorin also. Thorin's greed was epitomised at the moment when he discovered that Bilbo had given the Arkenstone to the Elvenking and Bard: he lifted Bilbo up, shouting, 'I will throw you to the rocks'. Upon his deathbed Thorin repented his ways, saying that "if more of us valued food and cheer and song above hoarded gold, it would be a merrier world."[22]

The epithet "Oakenshield" also comes from the Dvergatal. Eikinskjaldi means "Oakenshield", and it has long been considered the name of a Dwarf. However, because the name appears twice, both in Dúrinn's and Dválinn's line, it has also been suggested that it simply means "with an oaken shield".[24]

Thorin was portrayed by Richard Armitage.[27] Unlike many other adaptations where Thorin is depicted as white-haired, Thorin is portrayed as younger looking (in the original book he was the oldest of the Dwarves in the Company; in the movies he appears to be roughly in the middle of the thirteen age-wise). Thorin, however, does have streaks of gray in his black hair.

In the prologue which flashes back to the Sack of Erebor, Thorin is shown to be a natural leader, and is distressed when Thranduil and his army do not come to the Dwarves' aid. Later, during a flashback to the Battle of Azanulbizar (referred to as the Battle of Moria in these films), his natural leadership is again on display, when rallying the troops after maiming Azog the Defiler (Dáin Ironfoot, who killed Azog during this battle in the book, is not present at all).

Thorin shows up later than expected at Bag End. He is thoroughly skeptical of Gandalf's choice of Bilbo as the fourteenth member of the Company, but the Hobbit finally earns his approval after attempting to save him from Azog and his Orc pack. After this ordeal, Gandalf revives him on the Carrock.

Thorin is captured by the Elves of Mirkwood along with all of the other Dwarves. He refuses to bargain with Thranduil on order to set them all free, still holding a grudge over the Elven-king not helping his people while Smaug destroyed their home.

After the Dwarves are caught trying to steal weapons out of the armory in Lake-town, Thorin promises the people a share of the treasure if the Company is allowed to reclaim their kingdom. After Bilbo's audience with Smaug, he leads the Dwarves in an attempt to defeat the Dragon by drowning him in molten gold. The plan fails, however, and Smaug instead heads off in a rage to Lake-town.

While searching the treasure hoard inside the Mountain for the Arkenstone, Thorin increasingly falls prey to Dragon sickness. He begins to be paranoid that the other Dwarves are scheming against him. He orders the other Dwarves to put up barricades to prevent anyone else from entering the Mountain, even as the Battle of Five Armies commences. He eventually overcomes his sickness and comes to his senses, leading the members of the Company into battle.

On Ravenhill, he attempts to take out the Orc army's leader, and old nemesis, Azog (with the help of Fíli, Kíli and Dwalin). After his nephews are killed, Thorin takes on the Pale Orc one-on-one (and, in the process, gets Orcrist back from Legolas). He manages to get Azog to fall into a frozen lake, but the Orc stabs through the ice and mortally wounds him. With his last strength, Thorin plunges Orcrist into Azog's chest, finally killing him. Soon after, right before succumbing to his wounds, he makes amends with Bilbo, and dies right there on the lake.

Notes

↑ Different accounts dispute the exact location of this first meeting. One source states that it occurred at an Inn in Bree. Whilst another states that Thorin started talking to Gandalf when he overtook him on the road.